Generally, a door sash, which forms a window opening, is integrally disposed on an upper portion of a vehicle door body (an inner panel and an outer panel), which opens and closes a door opening of a vehicle body. The door sash is constituted of a metallic column and a metallic upper sash. An end portion of the upper sash is coupled to an upper end portion of the column of the door sash.
The columns and the upper sash may be constituted of two members: a channel member, which supports a window glass, and an inner member. This inner member is installed on the channel member to form a bag portion in consort with the channel member (e.g., refer to Patent Literature 1).